Babies born in April have a higher risk of developing multiple sclerosis (MS) later in life, says a new study.
The findings suggest that mothers pregnant during the autumn and winter months are most likely to give birth to those who would develop the condition.
Researchers attribute it to mother's lack of exposure to sunlight during this phase -- vital to vitamin D output, linked to genes thought to be associated with MS.
MS is a chronic, often disabling disease, that attacks the central nervous system (CNS), comprising the brain, spinal cord and optic nerves.
Symptoms may be mild, such as numbness in the limbs or severe, such as paralysis or loss of vision. The progress, severity and specific symptoms of MS are unpredictable and vary from one person to another.
Scientists have suggested that a lack of vitamin D could trigger a predisposition to MS in a person's genetic makeup, said a release by Multiple Sclerosis Society (MSS).
David McNiven, director MSS said: "These intriguing results add weight to the evidence that the environment and in particular sunlight plays a part in MS and we're pleased that scientists are piecing together the complex puzzle of what may cause this debilitating condition."
The findings were published in the European Journal of Neurology.